The present invention relates generally to compositions and methods for treating fuel hydrocarbons, and more particularly, to organic compositions having two different but functionally related end uses.
In one application, compositions made according to the invention serve to emulsify organic fuels such as gasoline, diesel fuel, kerosene, so-called jet fuel and other liquid hydrocarbons in water, thus providing the potential for extinguishing fires and rendering masses of these materials non-flammable. The compositions are compatible with foam-forming constituents to further their fire extinguishing potential in those applications wherein foam is desired.
In another aspect, the emulsifying ability of the materials can be effectively used to disperse concentrations of such hydrocarbon materials finding their way into soils and ground water to render the hydrocarbons water-transportable and readily subject to degradation by naturally occurring and/or synthetically prepared bacteria or other agents for degrading the hydrocarbons.
Still further, because of the wetting properties of the compositions, they can be effective as a fire extinguishing agent when the fuel is in solid form, i.e., filled natural or synthetic rubber such as is used in rubber tires or the like, and against more viscous but still flammable material such as lubricating oils and other heavy "cuts" of petroleum.
According to the invention, the inventive composition is able to be used by applying it either to surface or subsurface concentrations of hazardous or undesirable hydrocarbons, including masses of gasoline, oil and the like that are spilled on land, and which are intentionally or unintentionally disposed of in sewers, exposed to the soil or the air, or otherwise as the result of an accident of some sort. Chemical breakdown of the dispersed hydrocarbons can be accelerated by increasing the concentration of available bacteria for this purpose. In some cases, the surface active agent ("surfactant") composition itself can serve as a nutrient for the bacteria, thus enhancing its action in degrading the hydrocarbon materials.
In the past, the concept of utilizing surface active agents in water for treating fires has often been suggested. One aspect of the use of surfactants in firefighting is that such treatment can render the water "wetter," i.e., better able to penetrate into and through the surfaces of semi-solid materials.
Moreover, the ability of surfactant materials to create frothing or foaming has been used in an attempt to provide a barrier at the liquid-air interface, which barrier will block oxygen from access to vapor at the liquid surface, usually the surface of a mass of burning oil or gasoline. In this connection, it is well known that, particularly in a petroleum-based fire, the combustion occurs only in the vapor phase, wherein oxygen in large quantities is readily available to the vapors originating within the liquid. In a fire, the increase in temperature accelerates the liquid vaporation and hence the rate of combustion. In many instances, surface active agents, particularly when accompanied by agitation, serve to achieve a mix of liquid water and fuel, thus rendering the fuel less volatile and less susceptible to burning. However, prior approaches to formulating compositions for this purpose have been accompanied by a number of drawbacks, as referred to elsewhere herein.
Referring to another aspect of treating petroleum or like materials following an accident or disaster of some sort, such as an oil spill on land or at sea, the advantage has been taken of the ability of surfactants to disperse oils in water. However, in many cases, the surfactants used introduce drawbacks which partially or completely offset the advantages sought to be gained by their use. Thus, in many cases, surfactants were effective to reduce the surface tension between the oil and the water, causing the oil to spread out and form an exceptionally thin film on the surface of the water. While this may decrease the concentration of oil in a particular area, it was later discovered that it results in extremely adverse effects on marine wildlife. In one aspect, it was found that surfactant treatment exposed wildlife to smaller but still damaging amounts of oil over areas that were increased from a few square yards or acres to areas of many acres or even many square miles. In the case of large ocean oil spills, hundreds or thousands of square miles can be actually affected by a thin film of oil.
A number of other drawbacks and disadvantages also characterized the prior art use of surfactants in attempting to contain the ill effects of oil spills or the like. In some cases, the chemical nature of the surfactant, particularly the oleophilic portion of the surfactant, was itself hazardous or undesirable from an ecological standpoint. Thus, a number of years ago, it was determined that the simple matter of washing oily substances with certain surfactants would be effective to disperse the oil in surrounding water, but it was also found that the surfactant itself was highly persistent and resistant to biological degradation. For example, the use of many surfactants made from highly alkylated cyclopentanes was curtailed, but only when this adverse side effect was discovered.
Another dilemma that has faced workers dealing with oil and gasoline spills, for example, involves attempts to remove the offending material from streets, sidewalks, and lawns, for example, by introducing them into the sewer system. However, it is well accepted that such materials, as presented to the sewage system, are resistant to degradation by resident bacteria in the sewage treatment plants. This being the case, it is apparent that such oily materials are effectively even more resistant to degradation by the much lower concentrations of bacteria naturally occurring in the soil.
Referring to such disposal of petroleum wastes in sewers, this has been discouraged or legislated against because of the persistent nature of the oils and the like, and their long-term resistance to degradation. In extreme cases, oily residues washed into a sewer system can impede the intended operations of a sewage system as well as stubbornly resisting degradation of the contaminants themselves. Consequently, addressing oil spill problems has been difficult and problematical. If allowed to remain untreated, a fire or soil contamination hazard persists, and if treated with the wrong materials, alternative and sometimes equally undesirable hazards can be created.
Still further, while it has been suggested that for each individual oil spill or the like, cleanup workers might find a particularly suitable agent for the job, this is not really helpful. This is because such cleanup or firefighting personnel may not know in advance whether the major hazard is an existing fire, a potential fire, soil contamination, sewage system contamination, or emission of harmful vapors. Thus, it is not practical for emergency crews to be fully stocked with every possible type of chemical agent that might be useful when responding to an emergency.
Under these circumstances, it would be considered very advantageous if a single composition could be provided that would have excellent success when used as an addition to water for firefighting purposes, and which would not create undesirable side effects.
It would also be highly advantageous if there were a waterborne composition which could be used against bodies of hazardous waste such as petroleum spills and the like, and which would render them non-flammable as well as non-objectionably dispersible in ground water. In this connection, it will be understood that a main difficulty with many petroleum-based hazardous wastes is not so much that they never can be attacked by bacteria, but simply the extremely long time it takes for them to be degraded by soil bacteria in the form of naturally occurring microflora and microfauna.
In this connection, it will be understood that many hazardous waste, particularly petroleum wastes, are extremely insoluble in water and thus tend to stay in the soil near the spill area. It is believed that such materials are strongly absorbed onto the non-aqueous components of the soil and remain relatively safe from bacterial degradation for two reasons. One is that they are highly concentrated, and the other is that most bacteria are water-borne or tend to thrive in aqueous environments.
Such bacteria being effective roughly in proportion to their concentration, many bacteria are simply not sufficiently concentrated to degrade large, monolithic petroleum spills within a finite time, especially where the surface-to-volume area of such oily materials is low and the supply of bacteria is also low.
On the other hand, when very finely dispersed, such as by a highly effective surfactant, such materials may be destroyed much more quickly by bacteria, including those which may be naturally occurring, or those which may be supplied to the spill site for this purpose. A mixture of both types can also be used.
Thus, if it were possible to disperse oily materials into sufficiently fine particle sizes and reduce their strong absorption on soil, such materials could then be entrained in the aquifer. Once so dispersed, the oily materials could be biodegraded by water-borne bacteria within a reasonable time. In addition, or in the alternative, the water with the dispersed oils in it could be dealt with by "pump and treat" technology. In the latter connection, it has been found that while such "pump and treat" methods may be effective, their effectiveness depends on the assumption that the material to be treated is a waterborne material. In many cases, this is not functionally true in the sense that, while some materials are waterborne, there are other materials remaining in the soil which only become waterborne after the lapse of months or years, thus almost indefinitely prolonging the "pump and treat" period.
Referring again to prior practices, several attempts to achieve a dispersion of oily materials in water have been unsuccessful because the surfactants in effect increase the toxicity of the oil relative to aquatic life. In particular, many surfactants render the cell walls of animal and plant life more permeable to biological hazards, thus increasing the effective toxicity of certain materials to such marine life. This usually occurs with a surfactant where the oleophilic portion of the molecule is synthetic rather than naturally occurring.
Referring again to bacterial treatment, it would be further advantageous if the surfactant used would also serve as nourishment for the bacteria or make nourishment available from the substrate. It would also be advantageous if a composition of surfactants and other materials could fill the above requirements and also be compatible with foam-forming constituents.
In view of the failure of the prior art to provide a chemical composition for treatment in emulsifying petroleum presenting a fire or spill hazard, it is an object of the invention to provide an improved composition for such purpose.
Another object of the invention is to provide a composition which includes surfactants and other components which are essentially non-toxic, even when used in substantial concentrations.
A further object of the invention is to provide a composition which may be used to treat water used in dispersing petroleum and like wastes in water so as to lower the vapor pressure of such water and expose them to bacterial action.
A still further object of the invention is to provide a composition which, when added to water used to treat petroleum or other hydrocarbons, will free adsorbed hydrocarbons from the soil and convert them into waterborne materials of greatly reduced particle size, able to be degraded by naturally occurring or specially supplied or augmented bacteria.
Yet another object of the invention is to provide a treating composition for water which is usable in a variety of emergency response situations, including petroleum firefighting, and in treating water- and landborne petroleum spills and the like.
Another object is to provide a composition for treatment of petroleum which will render limited amounts of spilled petroleum compatible with sewage systems.
A further object of the invention is to provide a composition for firefighting which includes an especially effective surfactant action and further provide a foaming action and in which the surfactant component for dispersing oil in water is compatible with a stable, high density foam.
A still further object of the invention is to provide a method of treating petroleum to render it non-flammable and dispersible in such a way as to render it susceptible to bacterial attack.
Yet another object of the invention is to provide a method of soil treatment or remediation wherein contaminated soil may be treated by a mix containing specially blended surfactants that are able to render petroleum oils dispersible in ground water and able to be attacked by bacteria including bacteria supplied for the purpose of soil remediation.
Another object of the invention is to provide a chemical composition which is effective to disperse petroleum in such a way that the oil will assume extremely fine particle size and wherein the surfactant is not harmful to aquatic animal and vegetal life.
A further object of the invention is to provide a treating composition for petroleum which includes a surfactant made from an animal tallow modified by chemical treatments including ethoxylation and which further includes selected alcohols and organic carboxylic acids, rendering the mixture dispersible in water and providing a strong emulsifying action for petroleum based fuels and lubricants.
A still further object of the invention is to provide a chemical mixture which is non-harmful to naturally occurring plant and animal life, even when applied to or mixed with petroleum products.